Structure-Function Elucidation of Flavonoids by Modern Technologies
Dilip Ghosh, Pulok K. Mukherjee in Natural Medicines, 2019
Flavonoids have a variety of structures with interesting features. After the antioxidant properties of the flavonoids were deciphered (Thompson et al. 1976; Torel et al. 1986; Husain et al. 1987; Larson 1988), researchers were interested in structural elucidation of these phytochemicals. Structure–activity relationship (SAR) studies revealed the importance of different functional groups and their pharmacological effectiveness. Currently, deciphering biological functions from structural aspects is gaining momentum in our society. Structural elucidation, continual improvement and advancement in separation as well as spectroscopic techniques have made it easier to depict the exact structure of a flavonoid with increasing precision. As depicted by Davies et al. (2006), more than 7000 structures of various flavonoid classes are mentioned and nearly half of them were reported after 1993. This shows a clear implication of the technical advancement on structural elucidation. At later stages, lack of available materials due to the miniscule quantities of flavonoids in plant tissues posed a serious challenge for elucidating the structures properly. More recently, the availability of sensitive spectroscopic and chromatographic techniques has helped in achieving prominence for defining the structure of various flavonoids (Mabry et al. 1970; Markham 1982; Harborne 1998). A few of the major techniques used in modern biochemistry for elucidating the structures are discussed below.
Effect of Transport on Distribution of Radioions and Radiometabolites
Lelio G. Colombetti in Biological Transport of Radiotracers, 2020
Many factors can influence the transport and thus the biodistribution of the radiotracers (radioions or radiometabolites); some of the interrelated factors are (1) route of administration, (2) carrier concentrations and complexed or ionic species, (3) cell-membrane permeability (extracellular or intracellular accumulation) by a passive or active process, and (4) enzyme and hormonal stimulation or depression and the metabolic state, i.e., fasting, etc.1 An understanding of the transport process could provide greater insight into the development of radiotracers for selective and enhanced movement of the agent into cells of specific tissue such as bone, brain, kidneys, liver, marrow, myocardium, pancreas, prostate, and tumors. An earlier publication covered the basic aspects of the effect of transport on the distribution of radiotracers.1 The present chapter presents information about the effects of transport on the distribution of radiotracers currently in clinical use or under development. In the latter group are positron-emitting radionuclides such as 11C, 13N, or l8F, which are useful tracers for imaging and quantitation studies with recently developed positron imaging systems. These systems can be used to perform biochemistry in vivo. Quantitative time-course changes of radiotracer concentrations can be determined for specifically labeled amino acids, sugar, or fatty acids. In addition, the uptake and clearance of ions or gaseous radiotracers can be utilized to determine blood flow (perfusion) or ventilation.
The Twentieth Century
Arturo Castiglioni in A History of Medicine, 2019
The orientation of scientific studies toward biochemical research was evident in many signal discoveries, which have marked a new trend in research and in therapy. Biochemistry is, among all branches of medicine, the one in which the most significant progress has been achieved, and its revelations have had a direct influence on the conception and treatment of disease. This age has been called the age of proteins and enzymes, and it may be asserted that chemical studies and experiments have been predominant in the evolution of medical science and practice. Just as fifty years ago the physician was accustomed to start first from a microbiological concept and to consider microorganisms as the most important or maybe the only causative agents of a great number of diseases, now the trend is changed and we are convinced that a no less important and perhaps a more important role is played by conditions and occurrences that are to be regarded as chemical processes.
The mathematical relationship between COVID-19 cases and socio-economic indicators of OECD countries
Published in Pathogens and Global Health, 2022
Mehmet Cem Catalbas, Serkan Burken
Multivariate analysis can be defined as the relationship between datasets consisting of many observations or variables. It provides statistical analysis of data with numerous measurements and it aims to achieve a meaningful relationship between multiple observations or variables [15]. It can be obtained pattern or data structures between many observations and variables and thus, useful and effective mathematical models can be created for system defining. The multivariate analysis method has numerous utilization areas in literature. Some of these fields are medicine, image recognition and classification, pharmaceutical science, financial sector, social sciences, earth science and education [16]. It is used extensively in the field of medicine, genetics, public health, biochemistry. Multivariate analysis methods can be categorized according to the type of input variables. The categorization of multivariate analysis methods is shown in Figure 3 [17].
How to discover new antibiotic resistance genes?
Published in Expert Review of Molecular Diagnostics, 2019
Linda Hadjadj, Sophie Alexandra Baron, Seydina M. Diene, Jean-Marc Rolain
In 1940, before the use of penicillin in medical practice, Abraham and al. isolated in an Escherichia coli strain the first enzyme, named penicillinase, able to destroy penicillin [4]. This characterization was achieved using biochemistry and enzymology methods. Historically, the classification of β-lactamases was based on the functional characteristics of the enzymes or their primary structure [21]. Since the description of the nucleotide sequences of genes and the discovery of various new resistance genes, the classification evolved to take into account these developments [22].
The force-from-lipid principle and its origin, a ‘what is true for E. coli is true for the elephant’ refrain
Published in Journal of Neurogenetics, 2022
Boris Martinac, Ching Kung
Force is basic: 4 pN (4 × 10−12 N) breaks a hydrogen bond; 1,600 pN breaks a C-C covalent bond. Chemistry, including biochemistry, can be viewed as mechanics by extension and examined by molecular dynamics/quantum mechanical simulations. Consider that the bilayer not only can be stretched by external forces, but is a compartment with internal forces, in which all membrane proteins operate, many more force-related mechanisms will be revealed in future research. Stay tuned.